Spark plug



April 21, 1925.

D. SPRADA SPARK PLUG Filed May 24, 1925 To all wko/ml imag/ concern:

Patented Apr. 21,192.5.

. e UNITED e STA TES;

DOMINICK SPRAIDA, F BUFFALO, NEW YORK.'

'SPARK PLUG.` n

` Application med May 24, 1923. semi No.'e41,os4.

Be it known that I, DOMINrcn SPRADA, a citizen of the United yStates, residing at Buffalo, in the county of Erie and Sta-te 'of New York, have invented certain new kand useful Improvements in Spark Plugs, of which the following is a specification.v

. My invention relates to improvements in spark plugs for internal combustion engines, and one of its objects is to provide 'a new and novel device ofthat character having a plurality of sparking gaps so arranged and the electrodes forming the same are so supported that the possibilities of the accumulation of carbon or other matter tending to foul the same will be reduced to the minimum.

It also has for its object the provision of a spark plug having an axial electrode provided with an insulation terminal of considerable size, which is spherical in formation and preferably glazed and through Vwhich a plurality of electrodes extend for co-operation with the axial electrode and with the shell of the spark plug. f

l/Viththe above and other objects in view, the invention consists in the novel features of construction, and in the arrangement and combination of parts to be hereinafter described and more particularly pointed out in the subjoined claims.

Fig. 1 is a sectional elevation of a portion of an automobile, showing the engine thereof equipped with myv improved spark plug. 3. Fig. 2 is a side elevation of one Aof the spark plugs.

Fig. 3 is a top plan view of the same.

Fig. 4 is an enlarged longitudinal section taken on line 4--4, F ig.l 3.

Fig. 5 is an enlarged longitudinal section taken on line 5 5, Fig. 2.

Fig. 6 is an enlarged transverse section taken on line 66, Fig. `4.

Referring to the drawingsin detail, the reference numeral 7 designates an automobile having an engine 8 provided with spark plugs 9 arranged according to my invention. My improvements are shown applied to a spark plug of common construction, but it is to be understood that such improvements may be applied to spark plugs of various kinds.

10 designates the casing of a spark plug, the casing shown in 4the drawing having an internal flange 11 vbetween its ends. The

upper or outer end of said casing is internally threaded, as at'12, and the other or inner end is slightly tapered and externally threaded, as at. 13. n

14 designates an insulating core inserted into the casing from the upper end and having 'a collar 15, said collar being adapted to receive support from the flange 11 of the casing; al suitable gasket l16, however, is interposed between said flange andicollar. The lower portion of said core is reduced in diameter and extends inwardly through the opening formed by the flange 11. A nut' 17 is threaded into the uppervend ofthe casing 10, andbetween said nut and collar 15 of the core, aV suitable gasket 18 is interposed. Upon tightening said nut 17, it will be forced against the collar 15 of the core, with the gasket 18 between the two, at the same time forcing said collar 15 against the internal flange 11 of the casing, with the gasket 16 between the two, thus establishing anair-tight connection between the core and casing. J

The core extends upwardly above the nut 17 and it has an electrode 19 extending axially therethrough, the upper or outer end kof which receives a screw nut 2O by means of which a current conducting wire mayl be connected to said electrode in the usual manner. The core insulates the electrode from the casing 10, which is grounded, as is common.

The casing 1() is provided at one side with a threaded opening 21 into which an elbow extension 22 of a valve casing 23 is threaded, said lvalve casing having an upward eXtension in the form of a cup 24;.- A passage 25 leads through said valve casing from said cup 24 to the interior vof the spark plug 10. Within the valve casing is a valve plug 26 through which a passage 27 is formed, said passage. being normally out of alinement `with the passage of the valve easing.

The valve plug is disposed at right angles tothe passage 25, and has connected to one .end thereof a lever` 28. Within the'elbow extension the passage 25 is enlarged, as `at 40, forming a shoulder 41 serving as a valve seat, and in this enlarged portion of the llo which the spark plug is secured, a stop pin 43 is passed" transversely through the elbow extension. The ball valve 42 is therefore free to move within the enlarged portion of the passage 25 between the valve seat il and the stop pin 43. Therefore, when the valve plugs 26 are opened to any desired degree, air is drawn through the spark plugs and into the cylinders during the suction stroke ofthepistons within the cylinder, and during the compression strokes of said vpistons said ball valves are 'forced against their seats il and prevent the escape oi the eX- plosive mixture through the plugs.

In automobile, the spark plugs are normally arranged in line, and when so disposed', the levers 28 of all the spark plugs are connected together by means of a rod 29, which extends rearwardly beyond the rearmost spark plug and has one end of a lever 3()V secured thereto, said lever being pivotally secured between its ends to a bracket 31 fastened lto the dashboar 32. The opposite end of said lever is pivotally connected to an actuating rod 33 extending rearwardly through said dashboard and through the instrument board 34, it having a knob or handle 35 at its rear end adapted to normally bear against said instrument board. With such parts in the position shown in Fig. l, the valve plugs 2G in the valves applied to the spark plugs have their passages 2 7 at right angles to the passages 25e1x`tending through the valve casings, thus closingthe lower or inner portions of the passages leading to the interior of the spark plugs.

If it is desired that air be drawn into the cylinders of' the engine on the suction stroke of lthe pistons therein for the purpose of inixingthe same with the explosive mixture drawn into said cylinders, the valve plugs or, more broadly considered, the valves, may be opened to the desired' degree, it being simply necessary to pull rearwardly on the actuating rod 33, whereupon the levers of the valves will be swung through an arc of a circle and the valve plugs rotated within the valve casings until the passages through saidy plugs register or partly register with the upper and lower portions of the passages through the valve casings, as may be desired.

ln cold weather it may also be desirable to prime the automobile, which is usually done by removing the spark plugs and pour- 4ing gasoline into the cylinders, and where spark plugs have heretofore been equipped with valves individually operated, it was necessary to open one valve after the other in orderv to deliver gasoline into the cylinders. By the time gasoline is delivered to all oi the cylindersythe valves closed, and the operator has returnedl to his seat to start the engine, considerable of the gasoline will be allowed to find its way downwardly into two, which the crank casing of the engine, and under such conditions the gasoline remaining in each cylinder as a thin film, will have lost more or less of itsk effectiveness.

lVith this invention, gasoline may be place-d in the cups 24 of the valves and the operator can enter the automobile and startthe same. lininediately upon rotating the engine shaft with his starter, he may grasp the handle 35 andv draw the rod 33 rearwardly, whereupon gasoline will be delivered into the engine cylinders, and in at least one or more et them such delivery will take place at theA moment that a spark is established therein by means ot the spark plug threaded thereinto. It will be apparent therefore that by having means on the spark plugs to retain a quantity of gasoline, and means to deliver said. gasoline at the time of starting the saine, the engine will start more readily than with the common form of priming devices now in use.

After the gasoline is delivered through all of the spark plugs, the actuating rod may be pushed forwardly to close the valves; or` the valves may be kept onen to any desired extent by adjusting the actuating rod, and thus air can be drawn into the spark plug and explosive chamber of the engine to be mired with the explosive mixture.

The electrode 19 extending through thel core has a porcelain or other insulation terininal 36, of considerable size, the same being spherical in formation and preferably glazed, and the extremity of said electrode is provided with a head 3T to prevent said spherical insulator from becoming detached. Extending through said insulator 36 are a phirality of electrodes 3S arranged parallel with said electrode 19 and they preferably have their upper ends curved toward the electrode 19 to i"orm spark gaps between the gaps serve as intensiiiers for the current passing through the spark plugs.

39 designates an electrode, which extends transversely underneath the spherical insulator 86, said electrode 39 being underneath and having one arm secured in the wall of the spark plug casing, and the other arm extending in a diametral direction So as to lie between they lower terminals olf the plurality oi electrodes 38. rEhe electrodes 38 may also have their lower ends bent inwardly. or toward the electrode 39, and between the electrodes 3S and 39 sparking gaps are provided, said gaps being wholly ontside ofthe spark plug casing so that when said casing is threaded into the eng-ine cylinder, the etiiective sparks at the last-inentioned spark gaps will occur within said engi-ne cylinder, while the intensifying sparks take place within the spark plug casing.

In the drawings I have shown four electrodes 3S, but any other number may be employed, as the use of a spherical insulator at the lower end of theaxial electrode 19 will enable any desired number of sparking electrodes to be used by merely positioning them at desired points through said spherical insulator and around the electrode 19.V

` at the effective spark gaps between the lower ends of the electrodes 38 and the electrode 39; thus assuring effective explosion.

Having thus describedvrny invention, What I claim is z-f 1. A spark plug comprising a casing, an insulation core Withinsaid casing having an axial electrode provided at its inner end with a glazed sphericalv insulator, and an electrode extending through said spherical insulator and in sparking relation to said axial electrode and to said casing.

2. A spark plug comprising a casing, an

insulation core Within said casing having an axial electrode, a spherical insulator mounted on the inner extremity of said axial electrode, and a plurality of electrodes extending through rsaid spherical insulator, the. inner end of each` of said plurality of electrodes being in spaced relation to said axial electrode and the outer ends thereof being in sparking relation to said casing.

3. A spark plug comprising a casing, an insulation core Within said casing having an axial electrode provided at its inner end with a spherical insulator, a second electrode extending from said casing, and a plurality of electrodes extending from said spherical insulator and in sparking relation to said second electrode, saidk plurality of electrodes being in current-conducting relation to said axial electrode.

4,-. A spark plug having a casing, an vinsulation core extending into said casing and having an axial electrode, a spherical .insulator secured to the inner end of said axial electrode, a plurality of electrodes in intensifying relation to said axial electrode and extending beneath said spherical insulator, and an electrode carried by said casing and in sparking relation to said plurality of electrodes.

5. A spark plug comprising a casing, an insulation core Within said casing having an axial electrode extending therethrough, a spherical insulator at the inner end of said axial electrode, a plurality of electrodes parallel with said axial electrode and having one of their ends in spaced but current-conducting relation to said axial electrode, and an electrode extending inwardly from said casing and disposed in spaced relation to said spherical insulation, said last-mentioned electrode being in sparking relation to said plurality of electrodes.

6. A spark plug comprising a casing, an insulation core fitting in said casing and having an axial electrode extending therethrough, the inner end of said electrode having a head, a spherical insulator secured to the headed inner end of said electrode and having a plurality of parallel electrodes extending therethrough and projecting in opposite directions therefrom, the inner projecting ends being in current-conducting relation to said axial electrode, and an electrode connected to said casing and being in sparking relation to the opposite ends to said plurality of electrodes. l

In testimony whereof I afiix my signature.

DOMINICK SPRADA. 

